Despite missing the beginning of FP2 due to an engine issue and time later because of a telemetry problem, Lewis Hamilton still topped the timesheets at Sepang.
The reigning World Champion's Friday afternoon got off to a delayed start due to an engine inlet system problem.
Out on track he managed just five laps before being told to "box, box, box, we have now lost telemetry completely."
That issue was soon sorted out and Hamilton was back on track, the last of the big names to venture out on the medium tyres for a qualifying style run.
And despite his earlier troubles he went quickest with a 1:39.790.
That put him 0.373s ahead of Ferrari's Kimi Raikkonen, who, had he stayed top, would have been the first in 20 sessions to beat Mercedes to the P1 slot.
On a sweltering hot day at the Sepang circuit, where the track temperature hovered in the high 50s and even reached into the 60s, Nico Rosberg was third fastest as his first flying lap on the medium tyres was ruined when he had a massive slide.
Rosberg was 0.428s off the pace, just ahead of Daniil Kvyat, Valtteri Bottas and Felipe Massa.
Sebastian Vettel, the last driver to get within a second of Hamilton's P1 time, had torrid time trying to put in a clean lap on the medium tyres.
His first qualifying style lap was ruined by Roberto Merhi's red flags while a spin of his own on his second forced him back into the pits. He reported front right brake concerns.
Max Verstappen completed the top eight ahead of Marcus Ericsson and Daniel Ricciardo.
FP2 was briefly stopped for six minutes when Roberto Merhi, struggling with rear grip and traction, lost the rear completely through Turn 11 and finished with his Manor F1 car beached in the gravel.
As for McLaren, Fernando Alonso and Jenson Button failed to shine as they were 16th and 17th, 2.7 and 2.8s off the pace respectively.
1 Lewis Hamilton Mercedes 1:39.790 16 laps
2 Kimi Raikkonen Ferrari 1:40.163 0.373 29 laps
3 Nico Rosberg Mercedes 1:40.218 0.428 26 laps
4 Daniil Kvyat Red Bull 1:40.346 0.556 17 laps
5 Valtteri Bottas Williams 1:40.450 0.660 31 laps
6 Felipe Massa Williams 1:40.560 0.770 27 laps
7 Sebastian Vettel Ferrari 1:40.652 0.862 29 laps
8 Max Verstappen Toro Rosso 1:41.220 1.430 30 laps
9 Marcus Ericsson Sauber 1:41.261 1.471 30 laps
10 Daniel Ricciardo Red Bull 1:41.799 2.009 8 laps
11 Pastor Maldonado Lotus 1:41.877 2.087 15 laps
12 Felipe Nasr Sauber 1:41.988 2.198 30 laps
13 Sergio Perez Force India 1:42.242 2.452 24 laps
14 Carlos Sainz Toro Rosso 1:42.291 2.501 31 laps
15 Nico Hulkenberg Force India 1:42.330 2.540 28 laps
16 Fernando Alonso McLaren 1:42.506 2.716 25 laps
17 Jenson Button McLaren 1:42.637 2.847 24 laps
18 Romain Grosjean Lotus 1:42.948 3.158 7 laps
19 Will Stevens Manor 1:45.704 5.914 12 laps
20 Roberto Merhi Manor 1:47.229 7.439 6 laps